PAGOSA SPRINGS, COLORADO — There’s a man standing on the bank of the Weminuche River in southern Colorado, telling 45 people who just shuffled off a tour bus how to restore a river. Stop, he says, chew a toothpick, and think about what you’re doing. “Sometimes you just need to sit and drink a beer.”

The man is Dave Rosgen, and he’s wearing a white cowboy hat and a belt buckle bigger than his fist. The outfit is authentic. When he’s not teaching stream restoration to government scientists and private consultants, Rosgen drives a Cadillac or rides cutting horses. National Geographic has called him “the Restoration Cowboy.”

A former U.S. Forest Service hydrologist, Rosgen struck out on his own and started a private firm, Wildland Hydrology, in 1985. His mission is to repair rivers that have been dammed and straightened, restore streambanks that have been armored with riprap and gabions (think of shopping carts filled with rock), and revive overgrazed floodplains and streambeds mined for gravel.

Rosgen embodies a new generation of river managers who champion “natural channel design” — the art of making rivers look and function like rivers rather than canals. During the last 15 years, over 14,000 hydrologists, engineers, biologists and ecologists from around the world have taken Rosgen’s courses.

But not everyone is ready to follow this brash, righteous cowboy into the sunset. Some academics and consultants believe Rosgen is misleading the masses with an oversimplified approach to a complex field of science.

Making rivers wild again

“What is fluvial geomorphology?” Rosgen asks the class on the opening morning of his introductory course. “Fluvial geomorphology is the study of landforms shaped by water.” The 45 participants hail from almost every Western state, as well as Michigan, North Carolina and New Jersey. They represent federal agencies, state environmental departments, tribes and private consultants, and they’ve each paid $1,500 to be here.

Over the course of five days, these pupils will learn the basics of Rosgen’s stream classification system, which uses a simple alphanumeric code (such as A2, C4, G1) based primarily on the river’s slope and the size of the gravel and rock in its bed. The system distills geomorphology, helping people to assess the health of streams and apply restoration techniques, which Rosgen also shares with the class.

Rosgen first tried his approach on the East Fork of the San Juan River in southern Colorado, one of the stops on his course’s bus tour. Back in 1986, the East Fork was an overgrazed stream with a braided channel and eroding banks. Rosgen restored the river to a single, meandering channel by using bulldozers and front-end loaders to arrange massive, native cottonwood trunks and quarter-ton boulders.

Rosgen’s students recognize the project’s success 17 years later: Trout hide in deep pools and willows cover gravel bars. Visits to other sites like the Weminuche and scores of projects by colleagues and former students win over the class before the end of the week.

“Without question, Dave is the most outstanding practitioner of small-river restoration in the United States,” says Luna Leopold, the father of modern fluvial geomorphology and son of conservation pioneer Aldo Leopold. But classification systems, by definition, simplify things — and it’s easy to oversimplify them. Few of Rosgen’s students have strong backgrounds in engineering and geomorphology and, on average, less than half of the class will return for additional advanced courses. So, Rosgen shows photos to the class of failed projects where people misapplied his system: “That’s what I call crapping your chaps in the saddle and sitting in it.”

A recipe for disaster?

Critics say Rosgen and his classes encourage messy saddles.

“It really takes a high level of expertise to restore a river,” says David Montgomery, a University of Washington geomorphology professor who has created his own stream classification system. “The thing I fear most about (Rosgen’s) courses is, we may be over-empowering people, making them think they know more than they do.”

An example is Uvas Creek in California, where, in 1995, a river manager tried to turn a braided channel into a meandering one. Uvas Creek had never been a meandering stream, and within four months of “restoration,” the creek had washed out, abandoned the single channel and returned to its braided wanderings.

Gillilan and others resent the “disciples” who question restoration projects that don’t use the Rosgen system. Adding to the resentment is the fact that the Forest Service has adopted Rosgen’s method as its standard classification system. Nearly a dozen states require contractors to take Rosgen’s courses in order to bid on stream monitoring or restoration projects.

Rosgen says the classification is “only the start” of a successful restoration project. “There’s 50 steps of analysis that I use in natural channel design,” he says. “That’s not a cookbook.”

Many critics recognize that the Rosgen classification system is a useful communication tool — and for now, at least, it’s the leading one of its kind.

“People say, ‘Rosgen, you make people dangerous. You teach them for one week,’ ” Rosgen tells his students, many of whom are already tackling stream restoration projects. “Well, after listening to your backgrounds, you’re already dangerous.”